Shocking closed-circuit television images of a young couple being swallowed up by a sinkhole that opened at their feet on a sidewalk in Seoul have gone viral on social networking sites.

The footage shows the duo plunging through the paved sidewalk, shortly after alighting from a bus in the South Korean capital, as other passers-by look on in horror.

The incident happened near an apartment construction site last Friday.

Firefighters rescued the young man and woman who fell 3m down. Both were not seriously injured and were discharged from hospital after receiving treatment.

On Tuesday, the Ministry of Land, Infrastructure and Transport ordered a nationwide survey of construction sites and their immediate surroundings to check for dangers like sinkholes and other subsidence.